A teacher asks her class what their parents do for a living.
Mary says, "My dad's a doctor." The teacher says, "That's great, can you spell doctor?"
"Yes, miss," replies Mary, "it's D-O-C-T-O-R."
"Well done," says the teacher, "Who's next?"
Billy puts his hand up and says, "My dad is in the police and he's a constable."
"That's very good, Billy," says the teacher. "Can you spell constable?"
"Yes, miss, it's C-U-N ..." at which point the teacher interrupts and says "No, Billy, try again."
"OK, miss, it's C-U-N ..." at which point the teacher jumps in again and says to Billy, "Not quite, why don't you practice in your spelling book and we'll come back to you in a minute? Right, who's next?"
"My dad works for Ladbrokes, miss," says little Johnny.
"Oh," replies the teacher. "Can you spell Ladbrokes?"
To which little Johnny replies, "No, miss, but I'll give you 5/4 on that Billy writes cunt in that book."